View source for 4ysv


==Structure of aminoacid racemase in apo-form==
<StructureSection load='4ysv' size='340' side='right'caption='[[4ysv]], [[Resolution|resolution]] 2.77&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4ysv]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Lentilactobacillus_buchneri Lentilactobacillus buchneri]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4YSV OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4YSV FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.77&#8491;</td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=4ysv FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4ysv OCA], [https://pdbe.org/4ysv PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4ysv RCSB], [https://www.ebi.ac.uk/pdbsum/4ysv PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4ysv ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/ILE2E_LENBU ILE2E_LENBU] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Crystal structures of Lactobacillus buchneri isoleucine 2-epimerase, a novel branched-chain amino-acid racemase, were determined for the enzyme in the apo form, in complex with pyridoxal 5'-phosphate (PLP), in complex with N-(5'-phosphopyridoxyl)-L-isoleucine (PLP-L-Ile) and in complex with N-(5'-phosphopyridoxyl)-D-allo-isoleucine (PLP-D-allo-Ile) at resolutions of 2.77, 1.94, 2.65 and 2.12 A, respectively. The enzyme assembled as a tetramer, with each subunit being composed of N-terminal, C-terminal and large PLP-binding domains. The active-site cavity in the apo structure was much more solvent-accessible than that in the PLP-bound structure. This indicates that a marked structural change occurs around the active site upon binding of PLP that provides a solvent-inaccessible environment for the enzymatic reaction. The main-chain coordinates of the L. buchneri isoleucine 2-epimerase monomer showed a notable similarity to those of alpha-amino--caprolactam racemase from Achromobactor obae and gamma-aminobutyrate aminotransferase from Escherichia coli. However, the amino-acid residues involved in substrate binding in those two enzymes are only partially conserved in L. buchneri isoleucine 2-epimerase, which may account for the differences in substrate recognition by the three enzymes. The structures bound with reaction-intermediate analogues (PLP-L-Ile and PLP-D-allo-Ile) and site-directed mutagenesis suggest that L-isoleucine epimerization proceeds through abstraction of the alpha-hydrogen of the substrate by Lys280, while Asp222 serves as the catalytic residue adding an alpha-hydrogen to the quinonoid intermediate to form D-allo-isoleucine.

Crystal structure of the novel amino-acid racemase isoleucine 2-epimerase from Lactobacillus buchneri.,Hayashi J, Mutaguchi Y, Minemura Y, Nakagawa N, Yoneda K, Ohmori T, Ohshima T, Sakuraba H Acta Crystallogr D Struct Biol. 2017 May 1;73(Pt 5):428-437. doi:, 10.1107/S2059798317005332. Epub 2017 Apr 19. PMID:28471367<ref>PMID:28471367</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4ysv" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Lentilactobacillus buchneri]]
[[Category: Hayashi J]]
[[Category: Mutaguchi Y]]
[[Category: Ohshima T]]
[[Category: Sakuraba H]]